Field of the Invention
The present invention relates to a transparent display panel capable of maximizing the aperture ratio of a transmissive portion, and a method of manufacturing the same.
Description of the Related Art
Flat display panels can have large or small screens and thus can be used in a wide range of applications. Currently, flat display panels are manufactured in a variety of types of displays and can be sorted into, for example, plasma display panels (PDPs), liquid crystal display panels (LCDs), and organic light-emitting diode display panels (OLEDs).
A transparent display panel displays information thereon to viewers and also transmits light from a background so that the viewers can see the background through the display panel. For a transparent display panel, the technology that allows viewers to easily see a background behind the transparent display panel is as important as the technology that efficiently displays information on the display panel. A typical display panel includes unit pixels, each consisting of a plurality of sub-pixels. Typically, the color of a unit pixel is represented by an appropriate combination of colors of the sub-pixels. By controlling colors of a plurality of unit pixels, information is displayed in a display panel.
Each of a plurality of sub-pixels is partitioned as a transmissive portion and a display portion. In the display portion, a sub-pixel represents a color of the display portion. Through the transmissive portion, viewers can see a background behind the display panel. For such a display panel in which every sub-pixel or pixel has a display portion and a transmissive portion, an appropriate ratio between the display portion and the transmissive portion is set, as well as the aperture ratio. A display panel includes driving circuits to drive sub-pixels, electrodes connected to the driving circuits, and electrodes for many other purposes. The aperture ratio of the transmissive portion of the transparent display panel cannot be increased due to the electrodes.
FIG. 1 is a schematic plan view of an existing transparent display panel including a transmissive area and a display pixel area. The transparent display panel 100 includes at least one transmissive area 120 and at least one display pixel area 130 on a substrate 110. The transparent display panel 100 can include a transmissive area 120, but is not limited thereto. Each unit pixel includes at least one sub-pixel, and sub-pixels are separated by a black matrix 111.
The sub-pixels in the display pixel area 130 can include red (R), green (G), blue (B) and white (W) sub-pixels. There exist elements for controlling the sub-pixels individually. At least one electrode for driving the display pixel area 130 can be disposed in the transparent display panel. Such electrodes may be one or more signal/data lines for delivering driving signals, or electrodes for supplying current to pixels and the like. In the transparent display panel 100, such electrodes are hidden by a black matrix 111 so as not to make the display difficult to view due to reflected light or the like. The ratio of the transmissive area 120 to the display pixel area 130 can be adjusted for the efficiency of the display pixel area 130 and transmissivity.
In particular, a transparent display panel includes electrodes formed in a display area and a non-aperture area that is covered by a black matrix to secure transmissivity of a transmissive area and the aperture ratio of the transmissive area. In the non-aperture area defined by the black matrix, driving signal electrodes for driving sub-pixels or electrodes for supplying current for driving the sub-pixels are disposed. Therefore, there exists a limit to expand the aperture ratio of the transmissive portion.